Pump metering device



1967 'A. e. BARSTOW ETAL 3,

PUMP METERING DEVICE Filed NOV. 10, 1964 w ww a 4 m m w 3 3 HI M A TTORNEYS United States Patent 3,392,577 PUMP METERING DEVIQE Alfred G. Barstow, 842i) Otis St, South Gate, Calif. 90280, and Russeil W. Burns, Venice, Calith; said Burns assignor to said Barstow Filed Nov. 10, 1964. Ser. No. 410,190 3 Claims. (Cl. 103-68) This invention relates generally to pumps, and more particularly to a novel pump metering device which will enable control of the volume of fluid per unit time delivered by the pump.

A preferred application of the present invention is in conjunction with reciprocating type pumps employed to pump relatively viscous fluids from large drums or vats so that such fluids may be transferred to smaller packaging containers or mixing chambers. The principles of the invention, however, are applicable to many other types of reciprocating pumps in which the quantity of material dispensed by the pump is a function of the pump stroke.

Pumps of the type in which the present invention is preferably employed are operated by air motors. More particularly, the pump includes an elongated tube or riser having a piston therein arranged to be reciprocated over a given distance within the tube. The piston includes a check valve means so that back and forth movement of the piston within the elongated tube will serve to lift or raise fluid within a drum or other container receiving the tube to the surface. The actuating rod for operating the pump piston in turn is caused to reciprocate by an air motor. This air motor normally takes the form of an air cylinder having a reciprocating air piston therein supplied from a source of pressurized air. The piston is arranged to reciprocate over the normal length of the air cylinder which in turn determines the stroke of the main pump piston. The rate of movement of the air cylinder will determine the material per unit time dispensed by the pump. Therefore, in order to vary the amount of material from the pump, the air supply valve for the air motor may be varied to speed up or slow down the reciprocation.

While proper air valve and air pressure adjustments will effect a change in the pump rate, it is difflcult to control accurately the degree of change. Thus, in instances wherein it is desired to deliver a given quantity of mate rial in a given time unit, a trial and error adjustment of the air valves to control the rate of pumping can be effected until the desired quantity per unit time is being dispensed. To repeat this rate of flow at a subsequent time is diflicult unless expensive auxiliary control equipment is provided to insure the same rate of reciprocation.

With the foregoing in mind, it is a primary object of this invention to provide a greatly improved pump metering device for use with reciprocating type pumps which enables an adjustment of the pump flow rate to be made without the necessity of adjusting the air valve or varying the air pressure in the air motor driving the pump to the end that a more simplified and more versatile controllable pump is provided.

More particularly, it is an object to provide a pump meter control for use on a reciprocating pump which may be consistently reset at various desired rates Without trial and error by means of simple visual observation of an indicator associated with the equipment.

Other objects of this invention are to provide a pump metering device for use with reciprocating pumps which may be adapted to presently available pumps Without appreciable alteration of the pump structure itself to the end that great economy is achieved in providing a flow control or metering device for such pumps.

Briefly, these and other objects and advantages of this invention are attained by providing a means to vary the stroke length of the air motor and thus the overall stroke ICE length of the pump rod and piston itself. By controlling the length of the stroke, there is provided a direct control of the amount of fluid or material being pumped per stroke. In case it is desired to deliver a given amount of fluid to fill a specific sized container, the length of the pump stroke may be adjusted to provide just this amount so that each container filled is provided with substantially the same quantity of material.

In accord with further features of the invention, there is provided an indicating means providing a visual indication of the setting of the pump metering device so that previously established pump flows may be repeated by visual observation of the indicating means without having to experiment with the actual quantities delivered.

A better understanding of the invention will be had by now referring to preferred embodiments thereof as illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of a drum containing viscous fluid together with a conventional type pump for transferring fluid from the drum;

FIGURE 2 is an enlarged fragmentary view partly in cross-section of a first embodiment of the pump metering device of this invention for use with the pump illustrated in FIGURE 1;

FIGURE 3 is another fragmentary view partly in crosssection of a modified type of pump metering device which may be used with the pump of FIGURE 1; and,

FIGURE 4 is a plan view partly in cross-section of the structure in FIGURE 3.

Referring first to FIGURE 1, there is illustrated a drum 10 including semi-viscous material 11. To remove this material, there is provided a pump including an elongated pump tube 12 and an air motor cylinder 13 supplied with pressurized air through an inlet line 14 for driving the pump. The extreme lower end of the pump tube or riser 12 includes an inlet opening 15 adjacent to the bottom of the drum It). An outlet line 16 in turn extends from a point adjacent to the upper end of the tube 1'2 for passing pumped material to an auxiliary container, such as the pail 17. The upper end of the air motor cylinder is closed off by a threaded cap 13.

The elements described thus far are entirely conventional and in order to change the flow rate of the pump, the practice heretofore has been to vary the air pressure valve in the air motor structure 13 to thereby vary the rate of reciprocation of the pump.

Referring now to FIGURE 2, there is shown the pump metering device of this invention together with details of the air mot'or described in FIGURE 1. As shown in FIGURE 2, the air motor cylinder 13 includes an internal air piston 19 incorporating an air valve means 20 and 20. A rod 21 for the piston 19 extends from the lower end of the cylinder 13 and is coupled to the main piston rod and piston (not shown) reciprocably mounted within the pump tube 12. Air pressure for driving the air motor is delivered through a small inlet passage 22 in the piston rod 21 to pass up to the air valve means 29 in the piston 19 and exhaust air is passed from the air valve means 2% in the piston 19 through an exhaust passage 22 in the piston rod.

The valve means 20 and 2% respectively include upper valve actuators 23 and 23 and upper ports 24 and 24, and lower valve actuator 25 and 25 and lower ports 26 and 2-5. The air flow through the passage 22 in the piston rod 21 is caused to pass out the lower outlet port 26 when the actuator 25 strikes a lower limit stop 27 and to pass out the upper outlet port 24 when the actuator 23 strikes an upper limit stop 28. For example, assume that the upper actuator 23 is depressed to open the upper port 24 in the piston 19, the lower port 26 being closed. Compressed air passed through the piston rod 21 will then pass out through the upper port 24 to the area above the air a piston 19. The piston 19 will thus be forced downwardly. When the bottom of the piston strikes the lower limit stop 27 defined in part by the upper structure of the pump tube 12, the actuator 25 will shift the valve to close the upper outlet port 24 and open the lower outlet port 26 so that compressed air will now pass through the piston 19 out the lower port 26 and thus urge the piston 19 upwardly. When the piston 19 strikes the upper limit stop which normally is defined by the cap structure 18 described in FIGURE 1, and would correspond in position to the stop means 28, the actuator 23 is moved to open the upper port 24 and close the lower port 26 so that compressed air will now be admitted to the upper portion of the piston 19. The actuators 23 and 25 for the valve 20 are similarly actuated to exhaust air on the upper and lower sides of the piston through passage 22' to atmosphere.

The piston 19 is thus caused to reciprocate back and forth as a consequence of the air pressure suppled through the supply line 14 into the air cylinder 13. This reciprocating movement in turn, and as described heretofore, operates the main piston within the pump tube 12 to effect pumping of the viscous fluid to the outlet line 16 described in FIGURE 1.

The pump metering device of the present invention as shown in FIGURE 2 includes a housing 29 having lower internal threads 30 which are designed to mate with the threads normally provided for the upper cap 18 described in FIGURE 1. Thus, in applying the device of this invention to the pump, it is only necessary to unthread the cap 18 and substitute therefor the housing 29.

As shown in FIGURE 2, the housing includes an internal bore 31 receiving an elongated internally threaded sleeve 32. The sleeve 32 is provided with a longitudinal key way 33 arranged to receive a key 34 projecting into the side of the housing 29. The sleeve is thus constrained against rotational movement but is free to move up and down longitudinally within the bore 31. The lower end of the sleeve 32 defines the stop means 28 and thus its position will determine the length of the stroke L of the air piston 19.

Threadedly received within the sleeve 32 is a lead screw 35 keyed at 36 to the upper end of the housing to prevent longitudinal movement of the lead screw 35 but permit rotation thereof. A knurled knob 37 connects to the upper end of the screw as shown to facilitate manual rotation of the screw. The arrangement is such that rotation of the knob 37 will rotate the lead screw 35 and thereby effect longitudinal movement of the sleeve 32 in an upward or downward direction in the bore 31. This movement in turn will adjust the position of the stop means 28 and thus vary the stroke length L of the air piston 19.

In order that consistent repositioning of the stop means 28 may be realized, there is provided a simple belt or O-ring 38 coupling the lower neck of the knob 37 to an indicator in the form of a counter 39. The counter 39 provides a visual indication of the number of turns of the lead screw 35 by the knob 37 from a given initial position. A given setting of the stop means 28 may thus be effected by turning the knob 37 until a precalibrated desired reading on the counter 39 is indicated. The counter 39 and O-ring belt 38 are so designed that the same may be revolved by a carriage 40 about the top of the housing for convenient circumferential positioning of the counter.

The operation of the pump metering device of FIGURE '2 will be evident from the foregoing description. When it is desired to vary the pump flow, it is only necessary to vary the length L of the stroke of the air piston 19. This length in turn is controlled by the position of the stop means 28. For example, if it is desired to increase the quantity of viscous fluid pumped for each stroke, the stroke length L of the air piston 19 is increased by turning of the knob 37 in a clockwise direction as viewed from the top to thread the lead screw 35 into the sleeve 32 4 thereby causing the sleeve 32 to move upwardly within the bore 31. To decrease the quantity of fluid metered per stroke of the pump, the lead screw is turned in an opposite direction by the knob 37 to lower the stop means 28 and thus decrease the overall length L of the stroke.

Referring now to FIGURES 3 and 4, there is shown a slightly modified means for changing the position of the stop means. In FIGURE 3 there is illustrated a housing 41 including a central bore 42 receiving an internally threaded sleeve 43. The lower end of the sleeve terminates in a stop means (not shown) similar to the stop means 28 of FIGURE 2 and is keyed to the housing in the same manner as illustrated in FIGURE 2. As is also the case in FIGURE 2, there is provided an internal lead screw 44 threadedly received within the sleeve 43. However, in contra-distinction to the embodiment of FIGURE 2, the upper portion of the lead screw 44 terminates in a first bevel gear 45. This bevel gear in turn is threadedly engaged by a second bevel gear 46, the axis of rotation of which forms a angle with the axis of the lead screw 44. A simple handle means 47 is connected to one side of the second bevel gear 46 to enable manual rotation thereof. A counter indicator 48 in turn is connected through a flexible shaft 49 to the other side of the second bevel gear 46 to indicate the rotative position of the lead screw 44.

By the arrangement illustrated in FIGURES 3 and 4, the counter 48 may be remotely located or disposed in any other convenient position for easy viewing. Further, by the provision of the bevel gears, the stop means may be adjusted from the side of the pump in a convenient manner.

From the foregoing descriptions, it will be evident that the present invention has provided a very simple and accurate means of metering material dispensed by the pump. Further, it will be evident that the device may be applied to conventional type reciprocating pumps in which the amount of material dispensed per stroke is a function of the stroke length, without appreciable alteration of the pump structure itself. Finally, as a consequence of the indicating counter means provided, it is possible to set the stop means at a desired position on a number of different pumps and at a subsequent time reestablish the same conditions by simply observing the counters While rotating the lead screws.

While the invention has been described with respect to varying the upper limit stop means for the reciprocating motion of the air piston, it is to be understood that the same principles are applicable to vary the lower stop means. In the latter instance, the overall length of the pump stroke will be changed in the same manner as described heretofore. Various modifications and changes that fall clearly within the scope and spirit of this invention will thus occur to those skilled in the art. The pump metering device is therefore not to be thought of as limited to the particular embodiments set forth merely by way of example.

What is claimed is:

1. In a fluid pump including an actuating rod mounted for reciprocation between first and second limit stops defining the stroke of said pump and wherein the quantity of liquid delivered during each reciprocation is a function of the length of said stroke, a pump metering device adapted to be secured to said pump, said device including a housing having a central bore; an elongated sleeve member longitudinally movable in said bore and having internal threads, one end of said sleeve constitutes a stop means defining one of said limit stops; keying means holding said sleeve member against rotation within said bore while permitting longitudinal movement thereof; and a lead screw threadedly received in said sleeve and keyed against longitudinal movement whereby rotation of said lead screw moves said sleeve in a longitudinal direction to vary the position of said stop means to thereby vary the length of said stroke.

2. A device according to claim 1, including indicating means connected to said lead screw for indicating the rotative position of said screw and thereby the position of said stop means.

3. A device according to claim 2, in which the exposed end of said lead screw terminates in a first bevel gear; a second bevel gear threadedly engaging said first bevel gear, the rotational axis of said second bevel gear being at right angles to the axis of said lead screw; handle means connected to one side of said second bevel gear to enable manual rotation thereof; and a rotative coupling means connected between the other side of said second bevel gear for rotation therewith and said indicating means.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 6/1921 Germany.

LAURENCE V. EFNER, Primary Examiner. 

1. IN A FLUID PUMP INCLUDING AN ACTUATING ROD MOUNTED FOR RECIPROCATION BETWEEN FIRST AND SECOND LIMIT STOPS DEFINING THE STROKE OF SAID PUMP AND WHEREIN THE QUANTITY OF LIQUID DELIVERED DURING EACH RECIPROCATION IS A FUNCTION OF THE LENGTH OF SAID STROKE, A PUMP METERING DEVICE ADAPTED TO BE SECURED TO SAID PUMP, SAID DEVICE INCLUDING A HOUSING HAVING A CENTRAL BORE; AN ELONGATED SLEEVE MEMBER LONGITUDINALLY MOVABLE IN SAID BORE AND HAVING INTERNAL THREADS, ONE END OF SAID SLEEVE CONSTITUTES A STOP MEANS DEFINING ONE OF SAID LIMIT STOPS; KEYING MEANS HOLDING SAID SLEEVE MEMBER AGAINST ROTATION WITHIN SAID BORE WHILE PERMITTING LONGITUDINAL MOVEMENT THEREOF; AND A LEAD SCREW THREADEDLY RECEIVED IN SAID SLEEVE AND KEYED AGAINST LONGITUDINAL MOVEMENT WHEREBY ROTATION OF SAID LEAD SCREW MOVES SAID SLEEVE IN A LONGITUDINAL DIRECTION TO VARY THE POSITION OF SAID STOP MEANS TO THEREBY VARY THE LENGTH OF SAID STROKE. 